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class="sidebar-link">面试官：如何判断一个元素是否在可视区域中？</a></li><li><a href="/fe/javascript/continue_to_upload.html" class="sidebar-link">面试官：大文件上传如何做断点续传？</a></li><li><a href="/fe/javascript/pull_up_loading_pull_down_refresh.html" class="sidebar-link">面试官：如何实现上拉加载，下拉刷新？</a></li><li><a href="/fe/javascript/single_sign.html" class="sidebar-link">面试官：什么是单点登录？如何实现？</a></li><li><a href="/fe/javascript/var_let_const.html" class="sidebar-link">var 、let 和 const 区别？实现原理是什么？</a></li><li><a href="/fe/javascript/null_undefined.html" class="sidebar-link">undefined与null的区别</a></li><li><a href="/fe/javascript/data_type.html" class="sidebar-link">数据类型</a></li><li><a href="/fe/javascript/js.html" class="sidebar-link">JavaScript</a></li></ul></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>TypeScript</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>ES6</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>Vue</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>Vue3</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>React</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>Webpack</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>Node.js</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>性能优化</span> <span class="arrow right"></span></p> <!----></section></li><li><section class="sidebar-group collapsable depth-0"><p class="sidebar-heading"><span>手写代码</span> <span class="arrow right"></span></p> <!----></section></li></ul> </aside> <main class="page"> <div class="theme-default-content content__default"><h1 id="深浅拷贝"><a href="#深浅拷贝" class="header-anchor">#</a> 深浅拷贝</h1> <p><img src="/assets/img/clone.6eb0cd8e.png" alt="clone"></p> <h2 id="一、数据类型"><a href="#一、数据类型" class="header-anchor">#</a> 一、数据类型</h2> <p>最新的 ECMAScript 标准定义了 8 种数据类型：</p> <ul><li>7种原始类型（String、Number、Boolean、Null、Undefined、BigInt、Symbol）：栈内存，使用 typeof 运算符检查。但 <code>typeof null === &quot;object&quot;</code></li> <li>引用类型（Object）：引用地址-栈内存，指向内容-堆内存，instanceof</li></ul> <h2 id="二、浅拷贝"><a href="#二、浅拷贝" class="header-anchor">#</a> 二、浅拷贝</h2> <p><strong>深拷贝和浅拷贝是只针对Object和Array这样的引用数据类型的</strong>。浅拷贝，引用类型拷贝的就是内存地址。下面简单实现一个浅拷贝：</p> <div class="language-js extra-class"><pre class="language-js"><code><span class="token keyword">function</span> <span class="token function">shallowClone</span><span class="token punctuation">(</span><span class="token parameter">obj</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">const</span> newObj <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token punctuation">}</span><span class="token punctuation">;</span>
    <span class="token keyword">for</span><span class="token punctuation">(</span><span class="token keyword">let</span> prop <span class="token keyword">in</span> obj<span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token keyword">if</span><span class="token punctuation">(</span>obj<span class="token punctuation">.</span><span class="token function">hasOwnProperty</span><span class="token punctuation">(</span>prop<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
            newObj<span class="token punctuation">[</span>prop<span class="token punctuation">]</span> <span class="token operator">=</span> obj<span class="token punctuation">[</span>prop<span class="token punctuation">]</span><span class="token punctuation">;</span>
        <span class="token punctuation">}</span>
    <span class="token punctuation">}</span>
    <span class="token keyword">return</span> newObj<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
</code></pre></div><p>在<code>JavaScript</code>中，浅拷贝的实现方式有：</p> <ul><li><code>Object.assign</code></li> <li><code>Array.prototype.slice()</code>, <code>Array.prototype.concat()</code></li> <li>使用拓展运算符实现的复制</li></ul> <h3 id="_1-object-assign"><a href="#_1-object-assign" class="header-anchor">#</a> 1. Object.assign()</h3> <p>Object.assign() 方法可以把任意多个的源对象自身的可枚举属性拷贝给目标对象，然后返回目标对象。但是 Object.assign()进行的是浅拷贝，拷贝的是对象的属性的引用，而不是对象本身。</p> <div class="language-js extra-class"><pre class="language-js"><code><span class="token keyword">var</span> obj <span class="token operator">=</span> <span class="token punctuation">{</span> a<span class="token operator">:</span> <span class="token punctuation">{</span>a<span class="token operator">:</span> <span class="token string">&quot;kobe&quot;</span><span class="token punctuation">,</span> b<span class="token operator">:</span> <span class="token number">39</span><span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">var</span> initalObj <span class="token operator">=</span> Object<span class="token punctuation">.</span><span class="token function">assign</span><span class="token punctuation">(</span><span class="token punctuation">{</span><span class="token punctuation">}</span><span class="token punctuation">,</span> obj<span class="token punctuation">)</span><span class="token punctuation">;</span>
initalObj<span class="token punctuation">.</span>a<span class="token punctuation">.</span>a <span class="token operator">=</span> <span class="token string">&quot;wade&quot;</span><span class="token punctuation">;</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>obj<span class="token punctuation">.</span>a<span class="token punctuation">.</span>a<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">//wade</span>
</code></pre></div><p>注意：<strong>当object只有一层的时候，是深拷贝</strong></p> <div class="language-js extra-class"><pre class="language-js"><code><span class="token keyword">let</span> obj <span class="token operator">=</span> <span class="token punctuation">{</span>
    username<span class="token operator">:</span> <span class="token string">'kobe'</span>
    <span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">let</span> obj2 <span class="token operator">=</span> Object<span class="token punctuation">.</span><span class="token function">assign</span><span class="token punctuation">(</span><span class="token punctuation">{</span><span class="token punctuation">}</span><span class="token punctuation">,</span>obj<span class="token punctuation">)</span><span class="token punctuation">;</span>
obj2<span class="token punctuation">.</span>username <span class="token operator">=</span> <span class="token string">'wade'</span><span class="token punctuation">;</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>obj<span class="token punctuation">)</span><span class="token punctuation">;</span><span class="token comment">//{username: &quot;kobe&quot;}</span>
</code></pre></div><h3 id="_2-slice-、concat"><a href="#_2-slice-、concat" class="header-anchor">#</a> 2. slice()、concat()</h3> <p>补充说明：Array的slice和concat方法不修改原数组，只会返回一个浅复制了原数组中的元素的一个新数组。</p> <div class="language-js extra-class"><pre class="language-js"><code><span class="token keyword">const</span> fxArr <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token string">&quot;One&quot;</span><span class="token punctuation">,</span> <span class="token string">&quot;Two&quot;</span><span class="token punctuation">,</span> <span class="token string">&quot;Three&quot;</span><span class="token punctuation">,</span> <span class="token punctuation">{</span> name<span class="token operator">:</span> <span class="token string">'Jimmy'</span><span class="token punctuation">}</span><span class="token punctuation">]</span>
<span class="token keyword">const</span> fxArrs <span class="token operator">=</span> fxArr<span class="token punctuation">.</span><span class="token function">slice</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span>
fxArrs<span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token string">&quot;love&quot;</span><span class="token punctuation">;</span>
fxArrs<span class="token punctuation">[</span><span class="token number">3</span><span class="token punctuation">]</span><span class="token punctuation">.</span>name <span class="token operator">=</span> <span class="token string">'Bob'</span><span class="token punctuation">;</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>fxArr<span class="token punctuation">)</span> <span class="token comment">// [&quot;One&quot;, &quot;Two&quot;, &quot;Three&quot;, { name: 'Bob'}] // 基础类型未改变，引用类型的值改变了</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>fxArrs<span class="token punctuation">)</span> <span class="token comment">// [&quot;One&quot;, &quot;love&quot;, &quot;Three&quot;, { name: 'Bob'}]</span>
</code></pre></div><h3 id="_3-拓展运算符"><a href="#_3-拓展运算符" class="header-anchor">#</a> 3. 拓展运算符</h3> <div class="language-js extra-class"><pre class="language-js"><code><span class="token keyword">const</span> fxArr <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token string">&quot;One&quot;</span><span class="token punctuation">,</span> <span class="token string">&quot;Two&quot;</span><span class="token punctuation">,</span> <span class="token string">&quot;Three&quot;</span><span class="token punctuation">,</span> <span class="token punctuation">{</span> name<span class="token operator">:</span> <span class="token string">'Jimmy'</span><span class="token punctuation">}</span><span class="token punctuation">]</span>
<span class="token keyword">const</span> fxArrs <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token operator">...</span>fxArr<span class="token punctuation">]</span>
fxArrs<span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token string">&quot;love&quot;</span><span class="token punctuation">;</span>
fxArrs<span class="token punctuation">[</span><span class="token number">3</span><span class="token punctuation">]</span><span class="token punctuation">.</span>name <span class="token operator">=</span> <span class="token string">'Bob'</span><span class="token punctuation">;</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>fxArr<span class="token punctuation">)</span> <span class="token comment">// [&quot;One&quot;, &quot;Two&quot;, &quot;Three&quot;, { name: 'Bob'}]</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>fxArrs<span class="token punctuation">)</span> <span class="token comment">// [&quot;One&quot;, &quot;love&quot;, &quot;Three&quot;, { name: 'Bob'}]</span>
</code></pre></div><h2 id="三、深拷贝"><a href="#三、深拷贝" class="header-anchor">#</a> 三、深拷贝</h2> <p><strong>深拷贝会另外创造一个一模一样的对象，新对象跟原对象不共享内存，修改新对象不会改到原对象。</strong></p> <p>目前实现深拷贝的方法不多，主要是两种：</p> <h3 id="_1-json-parse-json-stringify"><a href="#_1-json-parse-json-stringify" class="header-anchor">#</a> 1. JSON.parse(JSON.stringify())</h3> <p>原理： 用JSON.stringify将对象转成JSON字符串，再用JSON.parse()把字符串解析成对象，一去一来，新的对象产生了，而且对象会开辟新的栈，实现深拷贝。</p> <p>但 <code>undefined</code>、<code>function</code>、<code>symbol</code>、正则、  <code>new Date()</code>、数字对象 会在转换过程中被忽略或不好使。</p> <div class="language-javascript extra-class"><pre class="language-javascript"><code><span class="token keyword">const</span> originObj <span class="token operator">=</span> <span class="token punctuation">{</span>a<span class="token operator">:</span><span class="token string">'a'</span><span class="token punctuation">,</span>b<span class="token operator">:</span><span class="token string">'b'</span><span class="token punctuation">,</span>c<span class="token operator">:</span><span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">,</span><span class="token number">2</span><span class="token punctuation">,</span><span class="token number">3</span><span class="token punctuation">]</span><span class="token punctuation">,</span>d<span class="token operator">:</span><span class="token punctuation">{</span>dd<span class="token operator">:</span><span class="token string">'dd'</span><span class="token punctuation">}</span><span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">const</span> cloneObj <span class="token operator">=</span> <span class="token constant">JSON</span><span class="token punctuation">.</span><span class="token function">parse</span><span class="token punctuation">(</span><span class="token constant">JSON</span><span class="token punctuation">.</span><span class="token function">stringify</span><span class="token punctuation">(</span>originObj<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>cloneObj <span class="token operator">===</span> originObj<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// false</span>
</code></pre></div><h3 id="_2-手写递归"><a href="#_2-手写递归" class="header-anchor">#</a> 2. 手写递归</h3> <p>递归方法实现深度克隆原理：<strong>遍历对象、数组直到里边都是基本数据类型，然后再去复制，就是深度拷贝</strong></p> <div class="language-js extra-class"><pre class="language-js"><code><span class="token comment">// 实现深度克隆---对象/数组</span>
<span class="token keyword">function</span> <span class="token function">deepClone</span><span class="token punctuation">(</span><span class="token parameter">target</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token comment">// 初始化变量 result 成为最终克隆的数据；判断数据类型</span>
    <span class="token keyword">let</span> result<span class="token punctuation">,</span> targetType <span class="token operator">=</span> <span class="token function">checkedType</span><span class="token punctuation">(</span>target<span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">if</span> <span class="token punctuation">(</span>targetType <span class="token operator">===</span> <span class="token string">'Object'</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        result <span class="token operator">=</span> <span class="token punctuation">{</span><span class="token punctuation">}</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token keyword">if</span> <span class="token punctuation">(</span>targetType <span class="token operator">===</span> <span class="token string">'Array'</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
        result <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
    <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{</span>
        <span class="token keyword">return</span> target<span class="token punctuation">;</span>
    <span class="token punctuation">}</span>
    <span class="token comment">// 遍历目标数据</span>
    <span class="token keyword">for</span> <span class="token punctuation">(</span><span class="token keyword">let</span> i <span class="token keyword">in</span> target<span class="token punctuation">)</span> <span class="token punctuation">{</span>
        <span class="token keyword">let</span> value <span class="token operator">=</span> target<span class="token punctuation">[</span>i<span class="token punctuation">]</span><span class="token punctuation">;</span>
        <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token function">checkedType</span><span class="token punctuation">(</span>value<span class="token punctuation">)</span> <span class="token operator">===</span> <span class="token string">'Object'</span> <span class="token operator">||</span> <span class="token function">checkedType</span><span class="token punctuation">(</span>value<span class="token punctuation">)</span> <span class="token operator">===</span> <span class="token string">'Array'</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
            result<span class="token punctuation">[</span>i<span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token function">deepClone</span><span class="token punctuation">(</span>value<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// 递归遍历获取到value值</span>
        <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{</span>
            result<span class="token punctuation">[</span>i<span class="token punctuation">]</span> <span class="token operator">=</span> value<span class="token punctuation">;</span>
        <span class="token punctuation">}</span>
    <span class="token punctuation">}</span>
    <span class="token keyword">return</span> result<span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token comment">// 定义检测数据类型的功能函数</span>
<span class="token keyword">function</span> <span class="token function">checkedType</span><span class="token punctuation">(</span><span class="token parameter">target</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    <span class="token keyword">return</span> <span class="token class-name">Object</span><span class="token punctuation">.</span>prototype<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">.</span><span class="token function">call</span><span class="token punctuation">(</span>target<span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">slice</span><span class="token punctuation">(</span><span class="token number">8</span><span class="token punctuation">,</span> <span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// [object Object] | [object Array]</span>
<span class="token punctuation">}</span>
</code></pre></div><h3 id="_3-lodash-clonedeep"><a href="#_3-lodash-clonedeep" class="header-anchor">#</a> 3. Lodash.cloneDeep()</h3> <p>该函数库也有提供_.cloneDeep用来做 Deep Copy</p> <div class="language-js extra-class"><pre class="language-js"><code><span class="token keyword">var</span> _ <span class="token operator">=</span> <span class="token function">require</span><span class="token punctuation">(</span><span class="token string">'lodash'</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
<span class="token keyword">var</span> obj1 <span class="token operator">=</span> <span class="token punctuation">{</span>
    a<span class="token operator">:</span> <span class="token number">1</span><span class="token punctuation">,</span>
    b<span class="token operator">:</span> <span class="token punctuation">{</span> f<span class="token operator">:</span> <span class="token punctuation">{</span> g<span class="token operator">:</span> <span class="token number">1</span> <span class="token punctuation">}</span> <span class="token punctuation">}</span><span class="token punctuation">,</span>
    c<span class="token operator">:</span> <span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">,</span> <span class="token number">2</span><span class="token punctuation">,</span> <span class="token number">3</span><span class="token punctuation">]</span>
<span class="token punctuation">}</span><span class="token punctuation">;</span>
<span class="token keyword">var</span> obj2 <span class="token operator">=</span> _<span class="token punctuation">.</span><span class="token function">cloneDeep</span><span class="token punctuation">(</span>obj1<span class="token punctuation">)</span><span class="token punctuation">;</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>obj1<span class="token punctuation">.</span>b<span class="token punctuation">.</span>f <span class="token operator">===</span> obj2<span class="token punctuation">.</span>b<span class="token punctuation">.</span>f<span class="token punctuation">)</span><span class="token punctuation">;</span> <span class="token comment">// false</span>
</code></pre></div><h2 id="四、区别"><a href="#四、区别" class="header-anchor">#</a> 四、区别</h2> <h3 id="赋值与浅拷贝"><a href="#赋值与浅拷贝" class="header-anchor">#</a> 赋值与浅拷贝</h3> <p>赋值：<strong>赋的其实是该对象在栈中的地址，而不是堆中的数据</strong>。</p> <p>浅拷贝：是按位拷贝对象，<strong>创建一个新对象</strong>，对原始对象属性值的一份精确拷贝。</p> <div class="language-js extra-class"><pre class="language-js"><code><span class="token comment">// 赋值</span>
<span class="token keyword">const</span> fxArr <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token string">&quot;One&quot;</span><span class="token punctuation">,</span> <span class="token string">&quot;Two&quot;</span><span class="token punctuation">,</span> <span class="token string">&quot;Three&quot;</span><span class="token punctuation">,</span> <span class="token punctuation">{</span> name<span class="token operator">:</span> <span class="token string">'Jimmy'</span><span class="token punctuation">}</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
<span class="token keyword">const</span> fxArrs <span class="token operator">=</span> fxArr<span class="token punctuation">;</span>
fxArrs<span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token string">&quot;love&quot;</span><span class="token punctuation">;</span>
fxArrs<span class="token punctuation">[</span><span class="token number">3</span><span class="token punctuation">]</span><span class="token punctuation">.</span>name <span class="token operator">=</span> <span class="token string">'Bob'</span><span class="token punctuation">;</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>fxArr<span class="token punctuation">)</span> <span class="token comment">// [&quot;One&quot;, &quot;love&quot;, &quot;Three&quot;, { name: 'Bob'}] // 原对象一同改变</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>fxArrs<span class="token punctuation">)</span> <span class="token comment">// [&quot;One&quot;, &quot;love&quot;, &quot;Three&quot;, { name: 'Bob'}]</span>

<span class="token comment">// 浅拷贝</span>
<span class="token keyword">const</span> fxArr <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token string">&quot;One&quot;</span><span class="token punctuation">,</span> <span class="token string">&quot;Two&quot;</span><span class="token punctuation">,</span> <span class="token string">&quot;Three&quot;</span><span class="token punctuation">,</span> <span class="token punctuation">{</span> name<span class="token operator">:</span> <span class="token string">'Jimmy'</span><span class="token punctuation">}</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
<span class="token keyword">const</span> fxArrs <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token operator">...</span>fxArr<span class="token punctuation">]</span><span class="token punctuation">;</span>
fxArrs<span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token string">&quot;love&quot;</span><span class="token punctuation">;</span>
fxArrs<span class="token punctuation">[</span><span class="token number">3</span><span class="token punctuation">]</span><span class="token punctuation">.</span>name <span class="token operator">=</span> <span class="token string">'Bob'</span><span class="token punctuation">;</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>fxArr<span class="token punctuation">)</span> <span class="token comment">// [&quot;One&quot;, &quot;Two&quot;, &quot;Three&quot;, { name: 'Bob'}] // 基础类型未改变，引用类型的值改变了</span>
console<span class="token punctuation">.</span><span class="token function">log</span><span class="token punctuation">(</span>fxArrs<span class="token punctuation">)</span> <span class="token comment">// [&quot;One&quot;, &quot;love&quot;, &quot;Three&quot;, { name: 'Bob'}]</span>
</code></pre></div><h3 id="深拷贝与浅拷贝"><a href="#深拷贝与浅拷贝" class="header-anchor">#</a> 深拷贝与浅拷贝</h3> <p>对于基本数据类型的拷贝，并没有深浅拷贝的区别，我们所说的深浅拷贝都是对于引用数据类型而言的。</p> <ul><li>浅拷贝：就只是复制对象的引用，如果拷贝后的对象发生变化，原对象也会发生变化。</li> <li>深拷贝：就是对目标的完全拷贝，引用和值都复制了。只要进行了深拷贝，它们老死不相往来，谁也不会影响谁。</li></ul> <table><thead><tr><th>类型</th> <th>与原数据是否指向同一对象</th> <th>值为基本数据类型时是否一同改变</th> <th>值为对象时是否一同改变</th></tr></thead> <tbody><tr><td>赋值</td> <td>是</td> <td>变</td> <td>变</td></tr> <tr><td>浅拷贝</td> <td>否</td> <td>不变</td> <td>变</td></tr> <tr><td>深拷贝</td> <td>否</td> <td>不变</td> <td>不变</td></tr></tbody></table> <h4 id="参考文献"><a href="#参考文献" class="header-anchor">#</a> 参考文献</h4> <ul><li><a href="https://zhuanlan.zhihu.com/p/56741046" target="_blank" rel="noopener noreferrer">浅拷贝与深拷贝 - 知乎<span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></li> <li><a href="https://github.com/axuebin/articles/issues/20" target="_blank" rel="noopener noreferrer">JavaScript基础心法——深浅拷贝<span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></li> <li><a href="https://juejin.im/post/6844903692756336653" target="_blank" rel="noopener noreferrer">深拷贝的终极探索（90%的人都不知道）<span><svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" focusable="false" x="0px" y="0px" viewBox="0 0 100 100" width="15" height="15" class="icon outbound"><path fill="currentColor" d="M18.8,85.1h56l0,0c2.2,0,4-1.8,4-4v-32h-8v28h-48v-48h28v-8h-32l0,0c-2.2,0-4,1.8-4,4v56C14.8,83.3,16.6,85.1,18.8,85.1z"></path> <polygon fill="currentColor" points="45.7,48.7 51.3,54.3 77.2,28.5 77.2,37.2 85.2,37.2 85.2,14.9 62.8,14.9 62.8,22.9 71.5,22.9"></polygon></svg> <span class="sr-only">(opens new window)</span></span></a></li></ul></div> <footer class="page-edit"><!----> <div class="last-updated"><span class="prefix">更新时间:</span> <span class="time">12/14/2021, 10:12:35 AM</span></div></footer> <div class="page-nav"><p class="inner"><span class="prev">
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